<!DOCTYPE HTML>
<html>
  <head>
    <meta charset="utf-8">
    <title>CSS mask-clip reference</title>
    <link rel="author" title="CJ Ku" href="mailto:cku@mozilla.com">
    <link rel="author" title="Mozilla" href="https://www.mozilla.org">
    <style type="text/css">
      svg {
        position: absolute;
        top: 10px;
        border: 1px solid black;
      }
    </style>
  </head>
  <body>
    <svg width="200" height="200" style="left: 10px;">
      <rect x="20" y="20" width="100" height="100" fill="blue"/>
    </svg>
    <svg width="200" height="200" style="left: 220px;">
      <rect x="50" y="50" width="50" height="50" fill="blue"/>
    </svg>
    <svg width="200" height="200" style="left: 10px; top: 220px;">
      <rect x="50" y="50" width="50" height="50" fill="green"/>
      <rect x="60" y="60" width="40" height="40" fill="blue"/>
    </svg>
  </body>
</html>
